Propeller.



No. 755,426. PATENTED MAR. 22, 1904.

' J I WOOD PROPELLEIL. APPLIOATION FILED JUNE 26. 1902. RENEWED AUG. 1a. 1903.

.NO MODEL.

A TTOHNE Patented March 22, 1904.

PATENT OFFICE.

JEROME I. WOOD, OF PHILADELPHIA, PENNSYLVANIA.

PROPELLER SPECIFICATION formingpart of Letters Patent No. 755,426, dated March 22, 1904. Application filed June 26, 1902. Renewed August 18, 1903. SerialNo. 169,943. (No model.)

To all whrmt it may concern.-

Be it known that I, JEROME I. WOOD, a citizen of the United States, residing in the city and county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Propellers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, of which" Figure 1 is an elevation of my improved propeller looking in a direction as from the bow toward the stern ,of a boat when the propeller is applied thereto. Fig. 2 is a similar view looking in the opposite direction. Fig. 8 is a view looking upwardly at Fig. 1. Fig. & is a side elevation of Fig. 3 looking in the direction of the arrow. Fig. 5 shows section taken, respectively, on planes 00 y .2 through a blade, Fig. 3.

The object of this invention is to provide an improved propeller for boats which shall be of simple construction, efficient, and possess certain marked advantages hereinafter mentioned.

Referring to the accompanying drawings, 1 denotes the bladesthree in the present instance2 the hub, and 3 the usual opening therethrough for the driving-shaft, to which the propeller is to be secured. Each of the blades is curvilinear in the direction of its length and straight transverselythat is to say, any and all lines drawn upon the inner and outer surfaces of a blade in planes at right angles to the length or chord of the curve of the blade will be straight lines. The two edges 1 and 1 of the blade are each substantially the arc of a circle; but neither edge can advantageously exceed a semicircle. The edges converge and meet at the outer free end of the blade and also substantially at their inner ends, being there, however, necessarily sufficiently widened, as shown, so as to afford a suitably strong connection with the hub 2. The blade is joined to the hub in such position,

as also shown in the drawings, that the edge 1, being the inner edge or that toward the bow of the boat, is substantially in a plane passing longitudinally through the major axis of the hub, and the plane of the outer edge is substantially at right angles to the plane of the edge 1*. Sections of the blade in planes at right anglesto both of said planes will be oblique theretofor example, sections 22 y 2, Fig. 5, made, respectively, in planes :2 1/ 2, Fig. 4, are oblique to the plane 0, Fig. 5,this being the plane of the edge 1. These sections are also oblique to the plane cl at right angles to plane 0, plane being that of the edge 1 and passing through the major axis of the hub. In the particular bladesshown the angle 0, Fig. 5,formed by the plane 0 and the side of the blade adjacent to the edge 1 is forty-five degrees, as is also the angle f, formed by the plane 03 and the side of the blade adjacent to the edge 1'. To lessen the pitch of the blade, (without changing the length thereof,) the angle 7 would be diminished and the angle 6 correspondingly increased, and to increase the pitch the angle f would be increased and the angle 0 correspondingly diminished, as indicated, respectively, by the lines g and it in the blade-section y, Fig. 5; but the pitch of the blade of the relative dimensions of those shown in the drawings cannot be diminished by making the obliquity of the blade such as would carry the edge 1 beyond its present position-that is, for example, as if the side of the blade-section be made to correspond with the line e', Fig. 5-for in such case the said edge would be an are greater than a semicircle, which would be of no advantage, but the contrary. If the angle f be diminished and angle 6 increased, as mentioned, the edge 1 will remain semicircular; but the edge 1 will be an are less than a semicircle which will touch the ends of the blade and the point in, Fig. 5that is, the highest point of the are or edge 1. If the angle f be increased and the angle a diminished, the edge 1 will remain semicircular and the edge 1 will be an are less than a semicircle which will touch the ends of the blade and the point Zthat is, the highest point of the arc or edge 1 It may also be stated generally that the extent and radius of the arcs of the respective edges of a blade will depend upon the relative length and pitch of the blade; but, as before stated, neither are should exceed a cemicircle.

Having described my invention, I shall briefly describe its mode of operation. When the propeller is driven to propel the boat't'or ward-that is, in the direction of the arrow in Figs. 1 and 2the blades throw the water di rectly aft in substantially straight lines, the water with which the face of the blade contacts leaving the same as, so to say, a columnar body whose width is indicated by the lines 9) n, Fig. 5, and. when the propeller is reversed to drive the boat baclnvardly the water will likewise be thrown directly forward, leaving the inner face of the blade as a column Whose width is indicated by the lines 0p in said figure.

Having thus described my invention, I claim as new and desire to secure by Letters Patent-- A propeller whose blades are curvilinear in JEROME L'W O01).

\Vitnesses: v

ANDREW V. Gi-zourn, \VAL'rnn O. PUsmr. 

